Downhole tool orienting subassembly

ABSTRACT

A downhole tool orienting subassembly includes a latch assembly having one or more latch keys and an orienting key coupled to an outer housing of the latch assembly. A latch coupling has a body and an internal latch profile defined on an inner radial surface of the body to receive the one or more latch keys and thereby secure the latch assembly to the latch coupling. A guide slot is defined on the inner radial surface to receive the orienting key and thereby rotationally orient the latch assembly with respect to the latch coupling.

BACKGROUND

Hydrocarbons can be produced from wellbores of varying complexity that traverse one or more hydrocarbon-bearing subterranean formations. Multilateral wellbores, for example, include any number of lateral wellbores extending from a parent wellbore. In an example implementation, a casing exit (alternatively referred to as a “window”) is provided in the parent wellbore at each lateral wellbore junction, each allowing the respective lateral wellbore to be drilled from the parent wellbore. The casing exit can be formed by positioning a whipstock in the parent wellbore and deflecting a mill laterally into the inner wall of the casing that lines the wellbore. The mill penetrates the casing to form the casing exit, following which a drill bit can be inserted through the casing exit to drill the lateral wellbore to a desired depth.

Lateral wellbores are generally drilled at an angular direction from the parent wellbore predetermined to maximize hydrocarbon recovery from surrounding subterranean formations. It is therefore necessary to form the casing exit at a corresponding azimuthal (circumferential) orientation relative to the parent wellbore, which includes positioning the whipstock within the parent wellbore such that its deflector face is rotationally oriented toward the location where the casing exit is to be milled. Properly positioning and orienting the whipstock within the parent wellbore can be accomplished by engaging a latch assembly operatively coupled to the whipstock on a latch coupling previously secured within the parent wellbore.

BRIEF DESCRIPTION OF THE DRAWINGS

The following figures are included to illustrate certain aspects of the present disclosure, and should not be viewed as exclusive embodiments. The subject matter disclosed is capable of considerable modifications, alterations, combinations, and equivalents in form and function, without departing from the scope of this disclosure.

FIG. 1 is an exemplary well system that may incorporate the principles of the present disclosure.

FIG. 2 is an enlarged view of a portion of the well system of FIG. showing an exemplary embodiment of the downhole tool orienting subassembly.

FIG. 3A is a partial cross-sectional side view of an embodiment of the latch coupling of FIG. 2.

FIG. 3B is an isometric side view of an embodiment of the latch assembly of FIG. 2.

FIG. 4A is a partial cross-sectional side view of another embodiment of the latch coupling of FIG. 2.

FIG. 4B is an isometric side view of another embodiment of the latch assembly of FIG. 2.

FIG. 5 is a partial cross-sectional side view of another embodiment of the latch coupling of FIG. 2.

DETAILED DESCRIPTION

The present disclosure relates generally to downhole subassembly systems and, more particularly, to an orientable downhole tool assembly used to orient a downhole tool, such as a whipstock, to a desired circumferential location.

The embodiments disclosed herein describe an orientable downhole tool assembly that can be used in multilateral wells to axially and rotationally orient a downhole tool within a wellbore. A downhole tool, such as a whipstock apparatus, is conveyable into the wellbore. A latch assembly may be operatively coupled to the downhole tool and may include one or more latch keys and an orienting key coupled to an outer housing of the latch assembly. A latch coupling is secured within the wellbore and has a body and an internal latch profile defined on an inner radial surface of the body to receive the one or more latch keys and thereby secure the latch assembly to the latch coupling. A guide slot may be defined on the inner radial surface to receive the orienting key and thereby rotationally orient the latch assembly with respect to the latch coupling and also rotationally orient the downhole tool to a desired angular orientation within the wellbore. In embodiments, where the downhole tool is a whipstock apparatus, a deflector surface of the whipstock apparatus may be rotationally oriented to the desired angular orientation and thereby able to properly deflect tools (e.g., mills, drills, etc.) to form a lateral wellbore. The embodiments described herein provide the ability to land and orient a latch assembly to a latch coupling and minimize the possibility of over torque of downhole components in deep and/or deviated multilateral wells.

Determining that a latch assembly is properly landed, and thus locked in both axial (up/down) and circumferential (azimuthal) orientation, is typically verified by both a torque signal and the application of weight applied to the tool string carrying the latch assembly into the well. When a known weight can be applied to the tool string without passing the latch assembly through a corresponding latch coupling, that is an indication that the latch keys have successfully landed and are aligned properly within the latch coupling. The ability of the latch assembly to hold torque is also further evidence that the latch keys are landed properly, but torque is not absolutely necessary to verify proper latch assembly engagement.

As an example, whipstocks are often conveyed into a well as coupled to a tool string with a shear bolt. The shear bolt is configured to fail (shear) with downward weight after the latch assembly properly engages the latch coupling and the whipstock is thereby properly oriented within the well. When the latch keys are properly landed in the latch coupling, the latch assembly can hold both torque and compression loads, as well as some tension load. However, locating and landing the latch assembly in the latch coupling often requires or results in large torsional loads applied to the tool string, which could prematurely sever the shear bolt. This is especially true in deep or extended reach wells. If the shear bolt fails prematurely, weight can no longer be applied to the tool string to verify that the latch assembly is properly landed. Moreover, such large torsional loads assumed by the tool string could also result in excessive torque being applied to any tools or components above the latch assembly.

FIG. 1 depicts an exemplary well system 100 that may incorporate the principles of the present disclosure. As illustrated, the well system 100 may include a semi-submersible platform 102 centered over a submerged oil and gas formation 104 located below a sea floor 106. A subsea conduit 108 or riser extends from the deck of the platform 102 to a wellhead installation 112 that includes one or more blowout preventers 114. The platform 102 has a hoisting apparatus 116 and a derrick 118 for raising and lowering a work string 120 within the subsea conduit 108. The work string 120 may comprise, for example, a string of tubulars connected end to end, such as drill pipe or production tubing, but may alternatively comprise coiled tubing without departing from the scope of the disclosure.

It is noted that even though FIG. 1 depicts the well system 100 as including the offshore oil and gas platform 102, the various embodiments of the present disclosure are equally well suited for use in or on other types of oil and gas rigs, such as any land-based oil and gas rig or rigs located at any other geographical site.

As depicted, a parent wellbore 122 has been drilled through the various earth strata, including the formation 104. A string of casing 124 is cemented into at least a portion of the parent wellbore 122. The term “casing” is used herein to designate a string of tubulars or pipe used to line a wellbore. The casing may actually be of the type known to those skilled in the art as “liner” and may be segmented or continuous, such as coiled tubing.

A casing joint 126 may be interconnected between elongate portions or lengths of the casing 124 and positioned at a desired location within the parent wellbore 122 where a lateral wellbore 128 is to be drilled. A downhole tool orienting subassembly 130 may be positioned within the casing 124 and/or the casing joint 126 and, as will be described below, portions thereof may form an integral part of the casing 124 and/or the casing joint 126. In some embodiments, the downhole tool orienting subassembly 130 may include a whipstock or deflector. In such embodiments, once secured within the parent wellbore 122, the downhole tool orienting subassembly 130 may be operable to deflect one or more cutting tools (i.e., mills) into the inner wall of the casing joint 126 such that a casing exit 132 is formed therein at a desired circumferential (azimuthal) location. The casing exit 132 provides a “window” in the casing joint 126 through which one or more additional cutting tools (i.e., drill bits) may be inserted in order to drill the lateral wellbore 128. In some embodiments, however, the casing joint 126 may be omitted from the well system 100 and the casing exit 132 may alternatively be formed in a corresponding section of casing 124, without departing from the scope of the disclosure.

While the parent wellbore 122 is depicted as having a single lateral wellbore 128 extending therefrom, the downhole tool orienting subassembly 130 can be used in parent wellbores having multiple lateral wellbores, each of which may use an individual downhole tool orienting subassembly as described herein for positioning and orienting a downhole tool. In addition, even though FIG. 1 depicts the parent wellbore 122 as extending substantially vertical, the embodiments described herein are equally applicable for use in wellbores having other directional configurations, such as horizontal, deviated, slanted, diagonal, combinations thereof, and the like. Moreover, use of directional terms such as above, below, upper, lower, upward, downward, uphole, downhole, and the like are used in relation to the illustrative embodiments as they are depicted in the figures, the upward direction being toward the top of the corresponding figure and the downward direction being toward the bottom of the corresponding figure, the uphole direction being toward the surface of the well and the downhole direction being toward the toe of the well.

FIG. 2 is an enlarged view of a portion of the well system 100 showing an exemplary embodiment of the downhole tool orienting subassembly 130 as positioned within the parent wellbore 122, according to one or more embodiments. The downhole tool orienting subassembly 130 may include various tools and tubular lengths configured to be interconnected downhole such that a downhole tool 202 will be properly oriented within the parent wellbore 122. The downhole tool 202 may comprise any tool, component, device, or mechanism that may be required to be oriented downhole to a predetermined angular orientation for proper operation. Accordingly, the downhole tool 202 may include, but is not limited to, a whipstock apparatus (e.g., a washover whipstock, a workover whipstock, a completion deflector, etc.), a first pass milling assembly, a wellbore isolation device, . . . , and any combination thereof. In the illustrated embodiment, the downhole tool 202 is depicted as a whipstock apparatus used to drill the lateral wellbore 128 (FIG. 1) in a predetermined direction. Accordingly, as discussed and described herein, the downhole tool 202 will be referred to as “the whipstock apparatus 202,” but the downhole tool 202 may refer to any of the aforementioned downhole tools or any downhole device requiring proper angular orientation within a wellbore and that may benefit from preventing over-torque while being properly oriented and secured downhole.

As illustrated, the downhole tool orienting subassembly 130 may include a latch coupling 204 and one or more casing subs 206 coupled to or otherwise forming an integral part of the casing 124. The casing sub 206 may encompass several downhole tools or subs known to those skilled in the art, such as a casing alignment sub used to ensure proper alignment of the latch coupling 204 relative to casing 124.

As described in more detail below, the latch coupling 204 may be configured to receive a latch assembly 208 and thereby secure the whipstock apparatus 202 in a desired axial and rotational orientation within the parent wellbore 122. As used herein, the term “latch coupling” refers to any type of anchoring device capable of being secured within the casing 124 and otherwise configured to interact with the latch assembly 208. The latch coupling 204 may include, for example, but is not limited to, a wellbore packer device, a wellbore bridge device, a wellbore plug device, any other type of wellbore isolation device, and the like. The latch assembly 208 may be configured to locate and couple to any of the above-referenced types of anchoring devices, without departing from the scope of the disclosure.

In the illustrated embodiment, the casing joint 126 is depicted as being interconnected with the casing 124. The casing joint 126 may be formed of an easily millable or drillable material, such as aluminum. In other embodiments, the casing joint 126 may be made of a composite material such as, but not limited to, fiberglass, carbon fiber, a combination thereof, or the like. The use of a composite material for the casing joint 126 may prove advantageous since cuttings resulting from milling through the casing joint 126 will not produce magnetically-charged debris that could magnetically-bind with downhole metal components or otherwise be difficult to circulate out of the well. In yet other embodiments, the casing joint 126 may be formed from or otherwise made of standard casing or could have a pre-milled window formed therein. It should be noted that, even though the latch coupling 204 and the casing joint 126 are depicted as being interconnected within the casing 124 proximate one another, those skilled in the art will recognize that other downhole tools or tubulars may alternatively be interconnected within the casing 124 between the latch coupling 204 and the casing joint 126.

The whipstock apparatus 202 may be run into the parent wellbore 122 within the casing 124 on a conveyance 210, such as jointed tubing (e.g., drill pipe, production tubing, etc.), coiled tubing, or the like. The whipstock apparatus 202 includes a deflector surface 212 operable to deflect a milling or drilling tool into the inner wall of the casing joint 126 to create the casing exit 132 (FIG. 1). The latch assembly 208 may be operatively coupled to or otherwise form an integral part of the whipstock apparatus 202. As used herein, “operatively coupled” means that the latch assembly 208 may be directly or indirectly coupled to the whipstock apparatus 202. As illustrated, the latch assembly 208 is arranged downhole from the whipstock apparatus 202.

The whipstock apparatus 202 is run into the parent wellbore 122 on the conveyance 122 to allow the latch assembly 208 to be received within the latch coupling 204, which is already secured within the parent wellbore 122 in a known azimuthal (circumferential) orientation. In some embodiments, the downhole tool orienting subassembly 130 may include a sensor sub 214 used to obtain real-time azimuth, inclination, and tool-face direction measurements of the whipstock apparatus 202 while advancing within the parent wellbore 122. The sensor sub 214 may comprise, for example, a measurement-while-drilling (MWD) tool, as known in the art. While shown axially interposing the whipstock apparatus 202 and the latch assembly 208, the sensor sub 214 may be alternatively be placed at other locations with respect to the whipstock apparatus 202. In some embodiments, for instance, the sensor sub 214 may be positioned downhole from the latch assembly 208, but could alternatively be positioned uphole from the whipstock apparatus 202, without departing from the scope of the disclosure.

Measurements obtained by the sensor sub 214 may be transmitted in real-time to a surface location (e.g., the platform 102) for consideration by a well operator. Such measurements may be transmitted via any known wired or wireless forms of downhole telemetry. Based on the real-time measurements obtained by the sensor sub 214, the well operator may be able to adjust the rotational orientation of the whipstock apparatus 202 so that the latch assembly 208 generally aligns with the latch coupling 204. For instance, the measurements obtained by the sensor sub 214 may help the well operator rotationally align the latch assembly 208 with the latch coupling to within +/−15° of a desired angular orientation for the whipstock apparatus 202. This rotational adjustment is referred to herein as a “coarse circumferential alignment.”

The latch assembly 208 includes one or more latch keys 216 that exhibit a unique outer profile configured to locate and engage a corresponding unique internal latch profile (not shown) of the latch coupling 204. As described below, the latch assembly 208 may include an orienting key (not shown) configured to locate and align with a guide slot (not shown) provided on the latch coupling 204, and thereby axially and rotationally align the latch assembly 208 within the latch coupling 204. Alignment using the orienting key and the corresponding guide slot is referred to herein as a “precise circumferential alignment.” Properly coupling the latch assembly 208 to the latch coupling 204 will axially and circumferentially orient the deflector surface 212 such that a mill subsequently conveyed downhole will be deflected into the inner wall of the casing joint 126 to form the casing exit 132 (FIG. 1) at the desired axial and azimuthal orientation.

FIG. 3A is a partial cross-sectional side view of an embodiment of the latch coupling 204, depicted as latch coupling 204 a, according to one or more embodiments. As illustrated, the latch coupling 204 a has a generally tubular body 302 that provides an upper connector 304 a and a lower connector 304 b, each suitable for connecting the latch coupling 204 a to other tools or tubulars via a threaded connection or a pinned connection.

The latch coupling 204 a provides an internal latch profile 306 defined on the inner radial surface of the body 302 at an intermediate location between the upper and lower connectors 304 a,b . The internal latch profile 306 may include a plurality of axially spaced grooves 308, shown as grooves 308 a-308 h, that extend circumferentially about the inner radial surface of the body 302. In some embodiments, the grooves 308 a-h extend circumferentially about the entire inner radial surface of the body 302. In other embodiments, however, one or more of the grooves 308 a-h may extend only partially about the inner radial surface of the body 302, without departing from the scope of the disclosure.

The internal latch profile 306 also provides or otherwise defines an upper groove 310 a and a lower groove 310 b positioned at opposing axial ends of the internal latch profile 306. The upper groove 310 a includes a lower square shoulder 312 and an upper angled shoulder 314, and the lower groove 310 b includes a lower angled shoulder 316 and an upper angled shoulder 318. The spacing, sizing, and general configuration of the grooves 308 a-h and the upper and lower grooves 310 a,b are depicted in FIG. 3A for illustrative purposes only and, therefore, should not be considered particularly limiting to the scope of the present disclosure.

The internal latch profile 306 also provides a plurality of circumferential alignment elements depicted as a plurality of recesses defined within the inner radial surface of the body 302. In the illustrated embodiment, there are four sets of two circumferential alignment elements that are defined in different axial and circumferential positions within the inner radial surface of the body 302. For example, a first set of two circumferential alignment elements 320 a and 320 b are defined within the latch coupling 204 a at substantially the same circumferential position but at different axial positions. A second set of two circumferential alignment elements 322 a and 322 b are defined within the latch coupling 204 a at substantially the same circumferential position but at different axial positions. A third set of two circumferential alignment elements 324 a and 324 b are defined within the latch coupling 204 a at substantially the same circumferential position but at different axial positions. Lastly, a fourth set of two circumferential alignment elements 326 a and 326 b are defined within the latch coupling 204 a at substantially the same circumferential position but at different axial positions.

As illustrated, the second set of circumferential alignment elements 322 a,b are angularly offset from the first set of circumferential alignment elements 320 a,b by 90°, and the third set of circumferential alignment elements 324 a,b are angularly offset from the second set of circumferential alignment elements 322 a,b by 90°. Likewise, the fourth set of circumferential alignment elements 326 a,b are angularly offset from the third set of circumferential alignment elements 324 a,b by 90°. In some embodiments, as illustrated, the circumferential alignment elements 320 a,b 322 a,b , 324 a,b , and 326 a,b extend only partially about the inner radial surface of the body 302.

The internal latch profile 306, including the circumferential alignment elements 320 a,b 322 a,b , 324 a,b , and 326 a,b , creates a unique mating pattern operable to cooperate with the latch keys 216 (FIGS. 2 and 3B) associated with the latch assembly 208 a (FIG. 3B) to axially and circumferentially anchor and orient the whipstock apparatus 202 (FIG. 2) in a desired circumferential orientation. The specific and unique internal latch profile 306 of the latch coupling 204 a can be created by varying the size and/or configuration of one or more of the grooves 308 a-308 h, the upper and lower grooves 310 a,b and the circumferential alignment elements 320 a,b 322 a,b , 324 a,b , and 326 a,b , or parameters thereof. For example, the thickness, number, and relative axial and/or circumferential spacing of the circumferential alignment elements 320 a,b 322 a,b, 324 a,b, and 326 a,b can be altered to provide a unique internal latch profile 306.

It is noted that each latch coupling in a well system (e.g., the well system 100 of FIG. 1) may have a unique latch profile that is different from the latch profile of another latch coupling. This enables selective engagement with a matching or mating set of latch keys for a particular latch assembly. The latch coupling 204 a as described herein merely illustrates the type of elements and combination of elements that can be used to create any number of unique latch profiles as contemplated by the present disclosure.

The latch coupling 204 a may further include at least one guide slot 328 (one shown) defined on the inner radial surface of the body 302. In some embodiments, as illustrated, the guide slot 328 may be defined within the latch profile 306 and otherwise at a location between the upper and lower grooves 310 a,b. Said differently, the guide slot 328 may be defined on the inner radial surface of the body 302 and axially overlap (occupy) at least a portion of the latch profile 306. In other embodiments, however, the guide slot 328 may be defined axially below the latch profile 306 and otherwise closer to the lower connector 304 b, as described below.

The guide slot 328 may provide a first or “uphole” end 330 a and a second or “downhole” end 330 b. The uphole end 330 a exhibits a first width 331 a and the downhole end 330 b exhibits a second width 331 b, where the first width 331 a is larger than the second width 331 b. In some embodiments, the first width 331 a may gradually taper inwardly to the dimension of the second width 331 b. As discussed below, the guide slot 328 may be configured to receive an orienting key 346 (FIG. 3B) included in the latch assembly 208 a (FIG. 3B) to rotationally orient the latch assembly 208 a with respect to the latch coupling 204 a, and thereby circumferentially orient the whipstock apparatus 202 (FIG. 2) in the desired circumferential orientation within the parent wellbore 122 (FIG. 2).

FIG. 3B is an isometric side view of an embodiment of the latch assembly 208 of FIG. 2, depicted as latch assembly 208 a, according to one or more embodiments. As illustrated, the latch assembly 208 a has an outer housing 332, which includes an upper sub 334 a and a lower sub 334 b. The upper sub 334 a provides an upper connector 336 a and the lower sub 334 b provides a lower connector 336 b, where each of the upper and lower connectors 336 a,b are capable of coupling the latch assembly 208 a to other tools or tubulars via a threaded or pinned connection. The upper connector 336 a, for example, may be coupled to the sensor sub 214 (FIG. 2) or may alternatively be coupled to the whipstock apparatus 202 (FIG. 2).

The outer housing 332 further includes a latch key housing 338 that defines a plurality of circumferentially-distributed, axially-extending key windows 340. In the illustrated embodiment, two key windows 340 are shown, while another two key windows 340 are positioned on the opposite (occluded) side of the latch key housing 338. Positioned within each key window 340 is a spring-operated latch key 216. Each latch key 216 is biased radially outward under the force of a biasing device, such as one or more springs or a plurality of Belleville washers disposed within the key housing 228.

Each latch key 216 exhibits a unique key profile 344 configured to mate with a corresponding unique latch profile 306 (FIG. 3A) of the latch coupling 204 a (FIG. 3A), and thereby enabling the latch assembly 208 a to be oriented and anchored to the latch coupling 204 a. As illustrated, the key profile 344 includes a plurality of radial variations (e.g., bumps, grooves, protrusions, etc.) that correspond with the mating grooves 308 a-308 h (FIG. 3A), the upper and lower grooves 310 a,b (FIG. 3A), and the circumferential alignment elements 320 a,b 322 a,b, 324 a,b, 326 a,b (FIG. 3A) of the latch profile 306 in order for the latch keys 216 to operably engage with or snap into the latch profile 306. In order for the latch keys 216 to locate and operably engage the latch profile 306, the latch assembly 208 a must be properly oriented both axially and circumferentially with respect to the latch coupling 204 a. Once properly oriented in both the axial and circumferential directions, the key profile 344 of each latch key 216 may be able to properly locate and engage the latch profile 306. As a result, the desired axial and circumferential orientation of the whipstock apparatus 202 (FIG. 2) will be established within the parent wellbore 122 (FIG. 2).

To help circumferentially orient the latch assembly 208 a with respect to the latch coupling 204 a, the latch assembly 208 a may further include at least one orienting key 346 (one shown) positioned on the outer housing 332. The orienting key 346 extends radially outward from the outer surface of the outer housing 332. Similar to the latch keys 216, the orienting key 346 may be spring-loaded so that the orienting key is able to radially retract and allow the latch assembly 208 a to pass through latch couplings that have a latch profile failing to match the key profile 344 of the latch keys 216.

In some embodiments, as illustrated, the orienting key 346 may interpose angularly (circumferentially) adjacent latch keys 216. In other embodiments, however, the orienting key 346 may be provided on the outer housing 332 axially below the latch keys 216 and otherwise closer to the lower sub 334 b, as described below. It should be noted that, while only one orienting key 346 is shown in FIG. 3B, more than one orienting key 346 may be used, without departing from the scope of the disclosure.

The orienting key 346 is configured to engage and otherwise be received within the guide slot 328 (FIG. 3A) of the latch coupling 204 a (FIG. 3A) and thereby help circumferentially orient the latch assembly 208 a within the latch coupling 204 a. The orienting key 346 may comprise a body 348 that has a first or “leading” end 350 a and a second or “trailing” end 350 b. The leading end 350 a may be configured to locate and enter the guide slot 328 at the uphole end 330 a (FIG. 3A). As illustrated, the body 348 may be tapered and otherwise angled outwardly from the leading end 350 a toward the trailing end 350 b so that the orienting key 346 can more easily locate the opening to the guide slot 328 at the uphole end 330 a. Said differently, the width of the body 348 may taper outwardly from the leading end 350 a toward the trailing end 350 b. In some embodiments, as illustrated, the width of the body 348 may also be tapered and otherwise angled outwardly from the trailing end 350 b toward the leading end 350 a, and thereby form a diamond-shaped body 348. At its widest point, the body 348 may exhibit a width 352 that is smaller than the second width 331 b (FIG. 3A) of the guide slot 328, thereby enabling the orienting key 346 to axially traverse the length of the guide slot 328.

With reference again to FIG. 2 in view of both FIGS. 3A and 3B, exemplary operation of orienting the whipstock apparatus 202 to a desired axial and azimuthal (circumferential) orientation within the parent wellbore 122 is now provided. As the whipstock apparatus 202 is run into the parent wellbore 122, the sensor sub 214 may operate to obtain real-time azimuth, inclination, and tool-face direction measurements of the whipstock apparatus 202. The measurements obtained by the sensor sub 214 and transmitted to a surface location (e.g., the platform 102) may allow a well operator to adjust the circumferential (azimuthal) orientation of the whipstock apparatus 202 to within +/−15° of a desired angular orientation for the whipstock apparatus 202. Adjusting the circumferential orientation of the whipstock apparatus 202 based on the measurements of the sensor sub 214 may result in a coarse circumferential alignment of the latch assembly 208 a with respect to the latch coupling 204 a.

Axial movement of the whipstock apparatus 202 in the downhole direction allows the latch assembly 208 a to enter the latch coupling 204 a. As the latch assembly 208 a enters the latch coupling 204 a, the orienting key 346 may be configured to locate and enter the guide slot 328 to provide a fine or “precise circumferential alignment.” The coarse circumferential alignment facilitated by the measurements of the sensor sub 214 generally aligns the leading end 350 a of the orienting key 346 with the uphole end 330 a of the guide slot 328. As the latch assembly 208 a advances further downhole, the leading end 350 a may be configured to locate the uphole end 330 a, which exhibits the enlarged first width 331 a. Once the leading end 350 a enters the uphole end 330 a, further downhole axial movement of the latch assembly 208 a will allow the body 348 to slidingly engage the tapering inner sidewalls of the guide slot 328 and thereby angularly orient the latch assembly 208 a such that each latch key 216 can locate and successfully engage the internal latch profile 306 of the latch coupling 204 a.

Once the key profile 344 of each latch key 216 locates and engages the latch profile 306, the desired axial and circumferential orientation of the whipstock apparatus 202 will be established within the parent wellbore 122. Since the latch assembly 208 is operatively coupled to the whipstock apparatus 202, properly coupling the latch assembly 208 to the latch coupling 204 will axially and circumferentially orient the deflector surface 212 to the desired orientation within the parent wellbore 122. Any cutting tools subsequently conveyed downhole, such as a mill, will be deflected into the inner wall of the casing joint 126 to form the casing exit 132 at the desired axial and azimuthal orientation for drilling the lateral wellbore 128. Moreover, once the casing exit 132 is formed, any additional tools used to drill and complete the lateral wellbore 128 may be deflected into the lateral wellbore 128 off the deflector surface 212.

In some scenarios, the coarse circumferential alignment facilitated by the measurements of the sensor sub 214 may fail to generally align the leading end 350 a of the orienting key 346 with the uphole end 330 a of the guide slot 328. In such scenarios, further downhole movement of the latch assembly 208 a with respect to the latch coupling 204 a will fail to provide the precise circumferential alignment between the latch assembly 208 a and the latch coupling 204 a and the latch keys 216 will fail to couple to the internal latch profile 306 of the latch coupling 204 a. Rather, the latch assembly 208 a will push through the latch coupling 204 a and the latch keys 216 will radially retract into the latch key housing 338 as the key profile 344 fails to properly engage the latch profile 306.

Failure to properly couple the latch assembly 208 a to the latch coupling 204 a may be sensed at the surface location (e.g., the platform 102 of FIG. 1) as the latch assembly 208 a pushes through the latch coupling 204 a. More particularly, an axial load of about 10,000 lbf to about 15,000 lbf may be placed on the latch assembly 208 a from the surface location and is sufficient to push the latch assembly 208 a through the latch coupling 204 a when the two components are not properly aligned. If the latch assembly 208 a is able to be pushed through the latch coupling 204 a at the given axial load, this may be an indication that the latch assembly 208 a is not properly aligned with the latch coupling 204 a.

In such scenarios, a well operator may retract (“pick up”) the whipstock apparatus 202 a short distance with the conveyance 210, rotate (either clockwise or counterclockwise) the whipstock apparatus 202 a predetermined angular amount, which correspondingly rotates the latch assembly 208 a, and then advance the whipstock assembly 202 back downhole for another attempt to couple the latch assembly 208 a to the latch coupling 204 a. In some cases, imparting small rotation to the conveyance 210 while raising or lowering the conveyance 210 may be more effective than rotating the conveyance 210 continually while advancing the conveyance in the downhole direction. In some embodiments, the predetermined angular amount to rotate the whipstock apparatus 202 may be about 5°, about 10°, or about 15°, but could alternatively be less than 5° or greater than 15°, without departing from the scope of the disclosure.

If rotation by the predetermined angular amount coarsely aligns the latch assembly 208 a with the latch coupling 204 a, as described above, advancing the latch assembly 208 a in the downhole direction will locate the leading end 350 a of the orienting key 346 within the uphole end 330 a of the guide slot 328 and thereby angularly orient the latch assembly 208 a such that each latch key 216 can successfully engage the internal latch profile 306 of the latch coupling 204 a. With the latch keys 216 properly engaging the latch profile 306, the latch assembly 208 a may be able to assume a downhole axial load of about 30,000 lbf to about 60,000 lbf before detaching from the latch coupling 204 a. Accordingly, a well operator can verify if the latch coupling 208 a is properly coupled to the latch coupling 204 a by applying the downhole axial load and seeing if the latch coupling 208 a pushes through the latch coupling 204 a. If, however, rotation by the predetermined angular amount fails to coarsely align the latch assembly 208 a with the latch coupling 204 a, the process of rotating the whipstock apparatus 202 by the predetermined angular amount and re-attempting engagement of the latch assembly 208 a with the latch coupling 204 a may be repeated until successful engagement is achieved.

FIG. 4A is a partial cross-sectional side view of another exemplary embodiment of the latch coupling 204 of FIG. 2, depicted as latch coupling 204 b, according to one or more embodiments. The latch coupling 204 b may be similar in most respects to the latch coupling 204 a of FIG. 3A and therefore may be best understood with reference thereto, where like numerals represent like elements or components not described again in detail. As illustrated, the latch coupling 204 b includes the body 302 that provides the upper and lower connectors 304 a,b and further includes the internal latch profile 306, as generally described above.

The latch coupling 204 b may also include the guide slot 328 defined on the inner radial surface of the body 302. Unlike the latch coupling 204 a of FIG. 3A, however, the guide slot 328 of the latch coupling 204 b is defined axially below the latch profile 306, such as at or near the lower connector 304 b. While the guide slot 328 is depicted in FIG. 4A axially below the latch profile 306, the guide slot 328 could alternatively be defined axially above the latch profile 306, such as at or near the upper connector 304 a, without departing from the scope of the disclosure. Again, the guide slot 328 provides the uphole and downhole ends 330 a,b, where the uphole end 330 a exhibits the first width 331 a and the downhole end 330 b exhibits the smaller second width 331 b.

FIG. 4B is an isometric side view of another exemplary embodiment of the latch assembly 208 of FIG. 2, depicted as latch assembly 208 b, according to one or more embodiments. The latch assembly 208 b may be similar in most respects to the latch assembly 204 b of FIG. 3B and therefore may be best understood with reference thereto, where like numerals represent like elements or components not described again in detail. As illustrated, the latch assembly 208 b includes the outer housing 332, which includes the upper and lower subs 334 a,b, the upper and lower connectors 336 a,b, and the latch key housing 338. As with the latch assembly 208 a of FIG. 3B, the latch key housing 338 of the latch assembly 208 b includes the key windows 340 with corresponding latch keys 216 positioned therein and biased radially outward under the force of a biasing device.

The latch assembly 208 b may further include the orienting key 346 positioned on the outer housing 332 and extending radially outward from the outer surface of the outer housing 332. Unlike the latch assembly 208 a of FIG. 3B, the orienting key 346 is provided on the outer housing 332 axially below the latch keys 216, such as at or near the lower sub 334 b. While the orienting key 346 is depicted in FIG. 4B axially below the latch keys 216, the orienting key 346 could alternatively be defined axially above the latch keys 216, such as at or near the upper sub 334 a, without departing from the scope of the disclosure. The orienting key 346 is again configured to engage and otherwise be received within the guide slot 328 (FIG. 4A) of the latch coupling 204 b (FIG. 4A) and thereby help circumferentially orient the latch assembly 208 b within the latch coupling 204 b. To accomplish this, the orienting key 346 includes the body 348 that has the leasing and trailing ends 350 a,b, where the leading end 350 a is configured to locate and enter the guide slot 328 at the uphole end 330 a (FIG. 4A).

Exemplary operation of orienting the whipstock apparatus 202 (FIG. 2) to the desired axial and azimuthal (circumferential) orientation within the parent wellbore 122 (FIG. 2) using the latch assembly 208 b and the corresponding latch coupling 204 b is substantially similar to the operation described above with reference to the latch coupling 204 a and the latch assembly 204 b of FIGS. 3A and 3B, respectively. Accordingly, discussion of orienting and engaging the latch assembly 208 b within the latch coupling 204 b will not be repeated.

FIG. 5 is a partial cross-sectional side view of another exemplary embodiment of the latch coupling 204 of FIG. 2, depicted as latch coupling 204 c, according to one or more embodiments. The latch coupling 204 c may be similar in most respects to the latch couplings 204 a and 204 b of FIGS. 3A and 4A, respectively, and therefore may be best understood with reference thereto, where like numerals represent like elements or components not described again in detail. As illustrated, the latch coupling 204 c includes the body 302 that provides the upper and lower connectors 304 a,b and further includes the internal latch profile 306, as generally described above.

The latch coupling 204 c may also include the guide slot 328 that receives the orienting key 346 (FIGS. 3B and 4B) to rotationally orient the latch assembly 208 a,b (FIGS. 3B and 4B). Unlike the latch couplings 204 a,b of FIGS. 3A and 4A, however, the guide slot 328 for the latch coupling 204 c is provided on a sub 502 that may be coupled to the latch coupling 204 c. As illustrated, the sub 502 has a generally tubular body 504 that includes an upper connector 506 a and a lower connector 506 b. In the illustrated embodiment, the lower connector 506 b may be configured to be coupled to the latch coupling 204 c at the upper connector 304 a via a threaded or pinned connection. In other embodiments, however, the upper connector 506 a may alternatively be configured to be coupled at the lower connector 304 b of the latch coupling 204 c. Accordingly, the sub 502 may be coupled to the latch coupling 204 c on either its uphole or downhole end, without departing from the scope of the disclosure.

The guide slot 328 may be provided on the body 504 of the sub 502 at various axial locations. In the illustrated embodiment, for example, the guide slot is depicted as being provided at or near the upper connector 506 a. Alternatively, the guide slot 328 may be provided at or near the lower connector 506 b, as shown in dashed lines. In some embodiments, the guide slot 328 may be defined into the inner radial surface of the body 502. In other embodiments, however, the guide sot 328 may be defined through the body 502 and otherwise generate an aperture in the body 502, without departing from the scope of the disclosure. As with prior embodiments, the guide slot 328 may include the tapered uphole end 330 a that exhibits the first width 331 a and the downhole end 330 b that exhibits the smaller second width 331 b.

Exemplary operation of orienting the whipstock apparatus 202 (FIG. 2) to the desired axial and azimuthal (circumferential) orientation within the parent wellbore 122 (FIG. 2) using the latch coupling 204 c and either of the latch assemblies 208 a,b (FIGS. 3B and 4B) is substantially similar to the operation described above with reference to the latch coupling 204 a and the latch assembly 204 b of FIGS. 3A and 3B, respectively. As the whipstock apparatus 202 is run into the parent wellbore 122, the sensor sub 214 (FIG. 2) may obtain real-time azimuth, inclination, and tool-face direction measurements of the whipstock apparatus 202 to allow the well operator to adjust the circumferential (azimuthal) orientation of the whipstock apparatus 202 to within +/−15° of the desired angular orientation. Continued axial movement of the whipstock apparatus 202 in the downhole direction allows the orienting key 346 to locate and enter the guide slot 328 to provide the precise circumferential alignment, and thereby angularly orient the latch assembly 208 a,b such that each latch key 216 (FIGS. 2, 3B, 4B) can locate and successfully engage the internal latch profile 306 the corresponding latch coupling 204 c.

As with prior embodiments, if the coarse circumferential alignment facilitated by the measurements of the sensor sub 214 fails to generally align the orienting key 346 with the guide slot 328, the whipstock apparatus 202 may be retracted a short distance, rotated (either clockwise or counterclockwise) the predetermined angular amount, and then advanced back downhole for another attempt to couple the latch assembly 208 a,b (FIGS. 3B and 4B) to the latch coupling 204 c. The process of rotating the whipstock apparatus 202 by the predetermined angular amount and re-attempting engagement of the latch assembly 208 a,b with the latch coupling 204 c may be repeated until successful engagement is achieved.

Embodiments disclosed herein include:

A. A downhole tool orienting subassembly that includes a latch assembly having one or more latch keys and an orienting key coupled to an outer housing of the latch assembly, a latch coupling having a body and an internal latch profile defined on an inner radial surface of the body to receive the one or more latch keys and thereby secure the latch assembly to the latch coupling, and a guide slot defined on the inner radial surface to receive the orienting key and thereby rotationally orient the latch assembly with respect to the latch coupling.

B. A well system that includes a downhole tool conveyable into a wellbore, a latch assembly operatively coupled to the downhole tool and having one or more latch keys and an orienting key coupled to an outer housing of the latch assembly, a latch coupling secured within the wellbore and having a body and an internal latch profile defined on an inner radial surface of the body to receive the one or more latch keys and thereby secure the latch assembly to the latch coupling, and a guide slot defined on the inner radial surface to receive the orienting key and thereby rotationally orient the latch assembly with respect to the latch coupling and rotationally orient the downhole tool to a desired angular orientation within the wellbore.

C. A method that includes conveying a latch assembly operatively coupled to a downhole tool into a wellbore, the latch assembly having one or more latch keys and an orienting key coupled to an outer housing of the latch assembly, receiving the latch assembly within a latch coupling secured within the wellbore, the latch assembly having a body and an internal latch profile defined on an inner radial surface of the body, receiving the orienting key within a guide slot provided axially above or axially below the internal latch profile and thereby rotationally orienting the latch assembly with respect to the latch coupling, and receiving the one or more latch keys with the internal latch profile and thereby securing the latch assembly to the latch coupling and rotationally orienting the downhole tool to a desired angular orientation within the wellbore.

Each of embodiments A, B, and C may have one or more of the following additional elements in any combination: Element 1: wherein the one or more latch keys comprise at least two latch keys circumferentially spaced from each other about the outer housing, and wherein the orienting key angularly interposes the at least two latch keys. Element 2: wherein the orienting key is positioned on the outer housing axially below the one or more latch keys. Element 3: wherein the orienting key comprises a body having a leading end and a trailing end, and wherein the leading end is configured to locate and enter an uphole end of the guide slot. Element 4: wherein a width of the body of the orienting key tapers outwardly from the leading end toward the trailing end. Element 5: wherein the width of the body of the orienting key tapers outwardly from the trailing end toward the leading end. Element 6: wherein the guide slot comprises an uphole end that exhibits a first width to receive the orienting key, and a downhole end that exhibits a second width smaller than the first width. Element 7: wherein the guide slot axially overlaps at least a portion of the internal latch profile. Element 8: wherein the guide slot is defined axially below or axially above the internal latch profile.

Element 9: further comprising a sensor sub operatively coupled to the downhole tool and used to obtain real-time azimuth, inclination, and tool-face direction measurements of the downhole tool. Element 10: wherein the one or more latch keys comprise at least two latch keys circumferentially spaced from each other about the outer housing, and wherein the orienting key angularly interposes the at least two latch keys. Element 11: wherein the orienting key is positioned on the outer housing axially below the one or more latch keys. Element 12: wherein the guide slot axially overlaps at least a portion of the internal latch profile. Element 13: wherein the guide slot is defined axially below or axially above the internal latch profile.

Element 14: wherein the guide slot is provided on a sub coupled to the latch coupling, and wherein receiving the orienting key within the guide slot comprises receiving the orienting key within the guide slot in the sub. Element 15: wherein receiving the orienting key within the guide slot is preceded by obtaining real-time measurements of the downhole tool with a sensor sub operatively coupled to the downhole tool, transmitting the real-time measurements to a surface location, and adjusting a circumferential orientation of the downhole tool based on the real-time measurements. Element 16: wherein the orienting key comprises a body having a leading end and a trailing end, and a width of the body of the orienting key tapers outwardly from the leading end toward the trailing end, the method further comprising locating and entering an uphole end of the guide slot with the leading end. Element 17: further comprising conveying a mill into the wellbore, deflecting the mill into an inner wall of the wellbore to form a casing exit at the desired angular orientation. Element 18: wherein receiving the orienting key within the guide slot is preceded by pushing the latch assembly through the latch coupling in a downhole direction, retracting the latch assembly back through the latch coupling in an uphole direction, rotating the downhole tool and the latch assembly a predetermined angular amount, and advancing the latch assembly through the latch coupling in the downhole direction and thereby receiving the orienting key within the guide slot.

By way of non-limiting example, exemplary combinations applicable to A, B, and C include: Element 3 with Element 4; Element 4 with Element 5; Element 6 with Element 7; and Element 6 with Element 8.

Therefore, the disclosed systems and methods are well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the teachings of the present disclosure may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered, combined, or modified and all such variations are considered within the scope of the present disclosure. The systems and methods illustratively disclosed herein may suitably be practiced in the absence of any element that is not specifically disclosed herein and/or any optional element disclosed herein. While compositions and methods are described in terms of “comprising,” “containing,” or “including” various components or steps, the compositions and methods can also “consist essentially of” or “consist of” the various components and steps. All numbers and ranges disclosed above may vary by some amount. Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range is specifically disclosed. In particular, every range of values (of the form, “from about a to about b,” or, equivalently, “from approximately a to b,” or, equivalently, “from approximately a-b”) disclosed herein is to be understood to set forth every number and range encompassed within the broader range of values. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. Moreover, the indefinite articles “a” or “an,” as used in the claims, are defined herein to mean one or more than one of the elements that it introduces. If there is any conflict in the usages of a word or term in this specification and one or more patent or other documents that may be incorporated herein by reference, the definitions that are consistent with this specification should be adopted.

As used herein, the phrase “at least one of” preceding a series of items, with the terms “and” or “or” to separate any of the items, modifies the list as a whole, rather than each member of the list (i.e., each item). The phrase “at least one of” allows a meaning that includes at least one of any one of the items, and/or at least one of any combination of the items, and/or at least one of each of the items. By way of example, the phrases “at least one of A, B, and C” or “at least one of A, B, or C” each refer to only A, only B, or only C; any combination of A, B, and C; and/or at least one of each of A, B, and C. 

1. A downhole tool orienting subassembly, comprising: a latch assembly having one or more latch keys and an orienting key coupled to an outer housing of the latch assembly; a latch coupling having a body and an internal latch profile defined on an inner radial surface of the body to receive the one or more latch keys and thereby secure the latch assembly to the latch coupling; and a guide slot defined on the inner radial surface to receive the orienting key and thereby rotationally orient the latch assembly with respect to the latch coupling.
 2. The downhole tool orienting subassembly of claim 1, wherein the one or more latch keys comprise at least two latch keys circumferentially spaced from each other about the outer housing, and wherein the orienting key angularly interposes the at least two latch keys.
 3. The downhole tool orienting subassembly of claim 1, wherein the orienting key is positioned on the outer housing axially below the one or more latch keys.
 4. The downhole tool orienting subassembly of claim 1, wherein the orienting key comprises a body having a leading end and a trailing end, and wherein the leading end is configured to locate and enter an uphole end of the guide slot.
 5. The downhole tool orienting subassembly of claim 4, wherein a width of the body of the orienting key tapers outwardly from the leading end toward the trailing end.
 6. The downhole tool orienting subassembly of claim 5, wherein the width of the body of the orienting key tapers outwardly from the trailing end toward the leading end.
 7. The downhole tool orienting subassembly of claim 1, wherein the guide slot comprises: an uphole end that exhibits a first width to receive the orienting key; and a downhole end that exhibits a second width smaller than the first width.
 8. The downhole tool orienting subassembly of claim 7, wherein the guide slot axially overlaps at least a portion of the internal latch profile.
 9. The downhole tool orienting subassembly of claim 7, wherein the guide slot is defined axially below or axially above the internal latch profile.
 10. A well system, comprising: a downhole tool conveyable into a wellbore; a latch assembly operatively coupled to the downhole tool and having one or more latch keys and an orienting key coupled to an outer housing of the latch assembly; a latch coupling secured within the wellbore and having a body and an internal latch profile defined on an inner radial surface of the body to receive the one or more latch keys and thereby secure the latch assembly to the latch coupling; and a guide slot defined on the inner radial surface to receive the orienting key and thereby rotationally orient the latch assembly with respect to the latch coupling and rotationally orient the downhole tool to a desired angular orientation within the wellbore.
 11. The well system of claim 10, further comprising a sensor sub operatively coupled to the downhole tool and used to obtain real-time azimuth, inclination, and tool-face direction measurements of the downhole tool.
 12. The well system of claim 10, wherein the one or more latch keys comprise at least two latch keys circumferentially spaced from each other about the outer housing, and wherein the orienting key angularly interposes the at least two latch keys.
 13. The well system of claim 10, wherein the orienting key is positioned on the outer housing axially below the one or more latch keys.
 14. The well system of claim 10, wherein the guide slot axially overlaps at least a portion of the internal latch profile.
 15. The well system of claim 10, wherein the guide slot is defined axially below or axially above the internal latch profile.
 16. A method, comprising: conveying a latch assembly operatively coupled to a downhole tool into a wellbore, the latch assembly having one or more latch keys and an orienting key coupled to an outer housing of the latch assembly; receiving the latch assembly within a latch coupling secured within the wellbore, the latch assembly having a body and an internal latch profile defined on an inner radial surface of the body; receiving the orienting key within a guide slot provided axially above or axially below the internal latch profile and thereby rotationally orienting the latch assembly with respect to the latch coupling; and receiving the one or more latch keys with the internal latch profile and thereby securing the latch assembly to the latch coupling and rotationally orienting the downhole tool to a desired angular orientation within the wellbore.
 17. The method of claim 16, wherein the guide slot is provided on a sub coupled to the latch coupling, and wherein receiving the orienting key within the guide slot comprises receiving the orienting key within the guide slot in the sub.
 18. The method of claim 16, wherein receiving the orienting key within the guide slot is preceded by: obtaining real-time measurements of the downhole tool with a sensor sub operatively coupled to the downhole tool; transmitting the real-time measurements to a surface location; and adjusting a circumferential orientation of the downhole tool based on the real-time measurements.
 19. The method of claim 16, wherein the orienting key comprises a body having a leading end and a trailing end, and a width of the body of the orienting key tapers outwardly from the leading end toward the trailing end, the method further comprising locating and entering an uphole end of the guide slot with the leading end.
 20. The method of claim 16, further comprising: conveying a mill into the wellbore; and deflecting the mill into an inner wall of the wellbore to form a casing exit at the desired angular orientation.
 21. (canceled) 